That’s a really great question anon.
And honestly i think her happy ending is a combination of things. Not one thing/one person in particular. I think its everything that makes up home.
It’s her parents and baby brother, finally having the family she always wanted growing up.
It’s being able to be a mother to Henry, watching him grow up and give him all the things she never had.
It’s Killian, having someone who loves her unconditionally. Who always put her first, who sees the best in her, who keeps his promises, who encourages her to be the best version of herself.
That is what I think Emma’s happy ending is. It’s Home. It’s Family.